Obesity and overweight conditions are a global epidemic and are the most frequent nutritional disorder in Western civilization. Currently, the conditions of “overweight” and “obesity” are classified by body mass index (“BMI”), which is a statistical measure of the weight of a person scaled according to height. From the period of 1988-1994 to the period of 1999-2000, the incidence of overweight adults augmented from 55.9% to 64.5% while the prevalence of obesity increased from 22.9% to 30.5%. The United States especially faces grave public policy concerns with respect to the morbidly obese, i.e. being over 100 pounds above their desirable weight or having one or more serious medical conditions in association with obesity.
In order to treat obesity, conventional procedures involve attempts to either 1) restrict food intake into the body via a restrictive bariatric procedure (a “Restrictive Procedure”), or 2) alter the anatomy of the small intestine or divert the peristalsis of a person's normal food intake past the small intestine to decrease caloric absorption via a malabsorptive bariatric procedure, which is commonly known as a gastric bypass (a “Malabsorptive Procedure”). It is also known to combine the two procedures such that both of the aforementioned techniques are employed jointly.
Each of the abovementioned procedures has advantages and disadvantages. The Malabsorptive Procedures, which entail short circuiting the gastric pouch, have previously been more successful in bringing about sustained weight loss; however, they are typically more difficult to perform, have higher rates of catastrophic post-operative complications, and produce long-term deleterious changes due to the rerouting of the alimentary flow. Restrictive Procedures have encountered more success than Malabsorptive Procedures because the Restrictive Procedures tend to be simpler, have fewer major complications, and do not disturb normal digestive tract continuity.
In Malabsorptive Procedures, an intestinal bypass is typically performed. This results in the exclusion of almost all of the small intestine from the digestive tract, such that a lower amount of calories and nutrients can be absorbed. One example of a specific Malabsorptive Procedure is the biliopancreatic diversion (“BPD”). BPD is a procedure in which about three-fourths (¾) of the stomach is removed in order to restrict food intake and decrease stomach acid production. The effect of this procedure is to alter the anatomy of the small intestine via the formation of an alimentary limb. The alimentary limb diverts the passage of food past the first portion of the small intestine, including the duodenum and jejunum, thereby preventing all of the bile and pancreatic juices from digesting the ingested food. As briefly noted above, this process does not come without significant risks.
Conversely, in Restrictive Procedures a passageway is generally constructed from the upper portion of the stomach to the lower portion, thereby preventing the stomach from storing large amounts of food and slowing the passage of food from the esophagus to the small intestine. Conventional Restrictive Procedures rely on the banding and/or stapling of the stomach to create a small pouch on the superior portion of the stomach near the gastroesophageal junction. When first created, this pouch can contain no more than approximately one (1) ounce of food and liquid, but typically later distends to store two (2) to three (3) ounces.
The lower outlet of the created pouch is nondilatable and is typically only one half (½) inch in diameter or smaller. The small pouch receives food and liquid directly from the esophagus and fills quickly. The pouch also diverts the passage of food and liquid to the lower portion of the stomach, thus avoiding storage of food in the stomach itself. Due to the pouch's size and the relatively narrow outlet into the larger stomach, the patient experiences early satiety, which in turn decreases appetite and results in weight loss. Purely Restrictive Procedures for obesity include adjustable gastric banding and vertical banded gastroplasty. These procedures do not affect the digestive process and thus do not result in the risks associated with Malabsorptive Procedures. In addition, Restrictive Procedures are safer than Malabsorptive Procedures and can be performed laparoscopically, thereby further reducing risks of complications.
In all Restrictive Procedures, the volume of the small pouch above the band can increase in size up to ten (10) times after the initial operation. Therefore, the pouch volume during surgery needs to initially be very small. To enable the patient to consume sufficient nutrition immediately after the operation considering such a small gastric pouch, the opening to the lower portion of the stomach must initially be relatively large. Thereafter, as the pouch volume increases, the opening must be subsequently reduced to enjoy optimal results of the procedure. In addition, the size of the opening should be gradually reduced during the first year after surgery as the gastric pouch increases in size.
One Restrictive Procedure, adjustable gastric binding (“AGB”), provides an adjustment means, thereby enabling minor post-operation adjustments of the size of the opening to the lower portion of the stomach. In AGB, a band is placed around the superior portion of the stomach to form a small pouch and a narrow passageway to the rest of the stomach. The band itself typically comprises a hollow silicone rubber band having an inflatable cavity. The inflatable cavity of the band is capable of being inflated with a fluid—typically an isotonic salt solution—through a tube that connects the band to an access port, which is typically located subcutaneously so that it may be easily accessed by the patient. Over time, the band may be tightened or loosened to modify the size of the opening to the lower portion of the stomach by increasing or decreasing the quantity of fluid within the cavity of the band. By adding liquid to the cavity of the band, the band expands radially inward and decreases the size of the opening to the lower portion of the stomach.
A great disadvantage of AGB, however, is that as a result of the direct manipulation of the bands, the rubber bands forming the gastric pouch tend to slip or wear away. In addition, in the conventional AGB process where the fluid is added to the band cavity by way of an injection into the access port, repeated injections into the same area increases the risk of infection in the area surrounding the access port. In addition, it is uncomfortable for the patient when the necessary post-operation adjustments of the opening are carried out by using a needle to access the port through the skin of the patient.
Similar to AGB, vertical banded gastroplasty (“VBG”) is a Restrictive Procedure that utilizes rubber bands as well as staples to create the small stomach pouch. Unlike AGB, however, VBG is not manually adjustable. The VBG procedure involves puncturing the stomach to create a pouch. Like AGB, VBG is prone to slippage and/or band deterioration. Additional complications also may arise with VBG, including staple-line disruption, which can result in stomach content leakage and/or serious infection. Such complications may require prolonged hospitalization with antibiotic treatment and even additional operations. Based on the associated risks, VBG has been classified by the American Medical Association as a “severely dangerous” operation.
Combined operations consisting of Malabsorptive and Restrictive Procedures are the most common bariatric procedures performed today. Such combined procedures restrict both food intake and the amount of calories and nutrients that the body is capable of absorbing. An example of a combined procedure is the Extended (Distal) Roux-en-Y Gastric Bypass (“RYGBP-E”) in which a stapling creates a small (approximately 15 to 20 cc) stomach pouch completely separated from the remainder of the stomach. The small intestine is divided just beyond the duodenum (the hollow tube connecting the stomach to the jejunum), and is re-arranged into a Y-configuration to enable outflow of food from the small upper stomach pouch, via a “Roux limb”. Accordingly, the small intestine forms the outlet of the newly formed stomach pouch, which empties directly into the lower portion of the jejunum, thus bypassing caloric absorption. The length of either segment of the intestine can be increased to adjust the levels of malabsorption.
Because the duodenum is bypassed in this procedure, poor absorption of iron and calcium can result in a decreased total body iron concentration and a predisposition to iron deficiency anemia. Additional complications of the RYGBP-E procedure include a condition known as “dumping syndrome”. Normally, the pyloric valve at the lower end of the stomach regulates the release of food into the bowel. Dumping syndrome is a condition in which the stomach contents rapidly pass into the small intestine resulting in extremely unpleasant conditions including nausea, weakness, sweating, faintness and, on occasion, diarrhea after eating. Because sugar passes especially rapidly into the bowel, some patients are unable to eat any form of sweets after RYGBP-E surgery.
Being obese has many health ramifications. Obesity is an important risk factor for a number of diseases and increases risk factors that heavily predispose for cardiovascular disease. In addition, systemic hypertension, pulmonary hypertension (left ventricular failure, chronic hypoxia), and coronary heart disease all occur with excessively high frequency in obese individuals and may be the source or influence in cardiac structure and function alterations. The risk of sudden cardiac death is also elevated in obese individuals.
Accordingly, a need exists for a safe, reversible, and effective method of treating obesity. The current Restrictive, Malabsorptive, and combination procedures present a high risk of several complications, including malnutrition, infections, vomiting, and recurrence resulting from band slippage or deterioration. There is therefore a need for a new restrictive laparoscopic technique that is reversible and not subject to the complications associated with the conventional procedures known in the art.